Understanding Stall in Wingsuit Flying

There is a common misconception that when flying in a wingsuit, one experiences a traditional aerodynamic stall. This is not entirely accurate. Wingsuits, with their very low aspect ratio, do not truly stall in the conventional sense. Instead, they transition into a state known as “mushing,” a term often used to describe the transitional phase between controlled flight and a free-fall descent. This transformation can be recognized by both auditory and tactile cues, which pilots use to adjust their flying techniques.

Aspect Ratio and Stall

Aspect Ratio: Wingsuit flying relies heavily on the wingsuit's aspect ratio, which is the wingspan divided by the chord length. A low aspect ratio means the wings have a short, rounded shape. Traditional aircraft designed for high-speed flight have wings with a high ratio, providing efficient lift. However, wingsuits with a low aspect ratio require pilots to manage the transition between flight and free-fall more carefully.

The Mush Phase

Mushing: When stalling occurs in conventional aircraft, there is a sudden loss of lift, accompanied by a sharp change in pitch and a nose-down attitude. For wingsuit flyers, the transition is different. As the wings begin to lose efficiency, the flyer may notice a gradual change in the way the suit behaves. This is the mush phase. During this period, the wingsuit becomes less controllable, and the flyer must adapt to prevent a complete transition to a upright falling posture. The crucial point is recognizing the mush phase as a warning sign that requires immediate action to regain control.

Recognizing the Mush Phase

Indicators: The pilots of wingsuits rely on a variety of indicators to recognize the onset of the mush phase. These can include:

Sound: A change in the sound of airflow over the wings can signal that the wingsuit is not producing as much lift. The rushing wind sound may become quieter, indicating a loss of speed and increasing speed of descent. Feeling: Tactile feedback from the suit is also critical. A flyer may notice a change in how the suit feels as they control it. If the suit feels too heavy or becomes difficult to maneuver, it could indicate that the transition is happening. Attitude: Monitoring the angle of attack can help. As the wingsuit transitions into the mush phase, the angle at which the flyer is gliding changes from a stable glide to a headwind into a stall.

In summary, recognizing the mush phase is vital for wingsuit flyers. By paying attention to the change in sound, feeling, and attitude, they can take corrective action to return to a stable flight or convert the descent into a controlled fall.

Practical Flying Techniques

Tactic 1: Adjust Speed: The first step in managing the approach to losing control is to regulate speed. By using the brakes or adjusting body position, the flyer can strive to maintain an optimal speed for stability. Excessive speed can lead to uncontrollable descent; conversely, too slow can also result in stall.

Tactic 2: Change Angle of Attack: Adjusting the angle at which the wingsuit meets the air can be another effective method. Rolling slightly or changing the orientation of the upper body helps to re-establish a more efficient lift profile.

Tactic 3: Use the Brakes: Modern wingsuits are designed with brakes that can help slow down and manage the descent. Deploying the brakes can transition the flyer from a mush phase to a controlled glide.

Tactic 4: Timing: Timing is crucial in the event of a mush transition. Anticipating the signs and acting promptly can save the flight, avoiding ending in a free-fall or a forced landing.

Conclusion

Wingsuit flying is an exhilarating but demanding sport that requires a deep understanding of aerodynamics and control. Recognizing the approach to a stall or mush phase is critical to ensuring safety and success. By leveraging auditory, tactile, and visual cues, coupled with practical flying techniques, wingsuit pilots can transform what could be a dangerous situation into a controlled descent. Mastery of these skills makes the difference between a thrilling flight and an unsafe fall.

Keywords: wingsuits, stall, approach recognition